Stationary LFP lithium-ion battery storage (containerised BESS) levelized cost of storage

Lower limit in the input guards.

Market range Exact by definition.

Unit multiplier in the CRF, the guards and the Customized switch.

Market range Exact by definition.

Protects divisions against a zero denominator.

Market range Exact by definition.

Converts a percent into a fraction.

Market range Exact by definition.

Converts a fraction into a percent; also the 100 % ceiling of the percent guards.

Market range Exact by definition.

kWh per MWh: converts the MWh energy capacity into the kWh basis of the cost figures.

Market range Exact by definition.

kW per MW: converts the rated power into the kW basis of the power-related cost.

Market range Exact by definition.

Hours in a 365-day year: ceiling of charge plus discharge hours, and base of the discharge capacity factor.

Market range Exact by definition.

Efficiency basis 1: NREL 2025 alone (costs, O&M and AC round-trip efficiency 85 % including cooling losses).

Efficiency basis 2, an assembly: NREL 2025 costs and O&M with the PNNL-33283 LFP AC-AC efficiency at the inverter (86.00 %, 2021). Not a PNNL cost case.

Efficiency basis 3, an assembly: NREL 2025 costs and O&M with the PNNL-33283 LFP AC-AC efficiency at the transformer, i.e. the grid point (82.59 %, 2021). Not a PNNL cost case.

Energy-related part of the all-in installed cost of a utility-scale Li-ion system, per kWh of nameplate energy. Multiplied by the energy capacity.

Market range No independent range cited for the energy/power split.

Power-related part (power conversion system, grid connection and other kW-driven items), per kW of rated power. This is what makes short durations dearer per kWh.

Market range No independent range cited for the energy/power split.

Published 4-hour all-in cost, shown in EUR as a reference beside the model value. At 4 h the split gives 241 + 372/4 = 334 USD/kWh by construction: an identity of the NREL equation, not an independent check.

Fixed O&M as a share of the total installed cost, per year. It is the only replacement model of the calculator: NREL sets it from the high end of published values so that it counteracts degradation and keeps the plant at rated capacity at about one cycle a day. No separate cell replacement is charged: adding one would double count.

Market range NREL ATB 2024 uses 2.5 % of the $/kW capital cost; PNNL-33283 uses 0.43 % of direct capital cost plus a separately costed augmentation.

Lower fixed O&M rate of the 2024 ATB, shown as a reference yearly cost only. The ATB page quoted here does not say that augmentation is inside it, so the model keeps the 2025 rate of 4 % that does.

AC round-trip efficiency of the NREL 2025 efficiency basis. HVAC and auxiliary losses are inside it, so they are not subtracted a second time.

Market range PNNL-33283 Table 4.4 LFP AC-AC: 82.59 % (transformer) to 86.00 % (inverter); Lazard LCOE+ 2025 key assumptions: 86-92 %.

AC round-trip efficiency of the PNNL 2022 LFP efficiency basis, metered at the inverter terminals (before the step-up transformer).

AC round-trip efficiency of efficiency basis 3, metered at the grid side of the transformer.

DC-side round-trip efficiency of the LFP block alone. The ratio of the case AC efficiency to it gives the round-trip efficiency of the power conversion, transformer and auxiliaries.

NREL service life paired with its cost and FOM figures. Used to show the LCOS at a 15-year life beside the 20-year default of PNNL and Lazard.

Market range PNNL-33283 and Lazard LCOE+ 2025 use 20 years.

Upper limit of the cycles slider and of the input guard: one cycle a day.

Lazard reference duty, used to show its yearly equivalent full cycles beside the user's duty.

Lazard reference duty (350 cycles a year), which is also the default of the cycles slider.

Lazard reference depth of discharge, default of the DOD slider and part of the Lazard reference duty.

Lazard charging price, shown in EUR as the reference behind the 24.9 EUR/MWh default of the charging price slider.

Converts the 2024 USD cost figures into EUR at the 2024 average rate. No EUR-native source with this energy/power split was found.

Size of the NREL cost anchor (60 MW x 4 h). The NREL specific CAPEX already carries the fixed project cost spread over this size; the size premium is the fixed cost x (1/E - 1/240 MWh), zero here.

Lower clamp of the specific CAPEX. It never binds inside the sliders: the lowest reachable value is the 8-hour, 1,000 MWh model value or the 200 EUR/kWh Customized floor.

Upper clamp of the specific CAPEX. It never binds inside the sliders: the highest reachable value is the 2-hour, 2 MWh model value or the 450 EUR/kWh Customized ceiling.

Default of the economic life slider (15-20 years: NREL 15, PNNL and Lazard 20). The NREL 4 % FOM keeps the plant at rated capacity, so 20 years is also the service life exported to project mode.

Default of the discount rate slider (5-8 %). It is a REAL rate, consistent with costs held in constant 2024 USD/EUR with no escalation.

Not used: PNNL pairs this low rate with a separately costed DC-block augmentation and a warranty, on a direct-cost base. Mixing it with the NREL all-in base would under-count O&M.

Low end of the Lazard 4-hour LCOS. Indicative: Lazard is levered, after tax and in its own dollar vintage, while this calculator is a pre-tax real annuity in 2024 money; the comparison places the result, it does not validate it.

High end of the Lazard 4-hour LCOS; same caveats as the low end.

Low end of the Lazard 2-hour LCOS; same caveats as the 4-hour range.

High end of the Lazard 2-hour LCOS; same caveats as the 4-hour range.

Published all-in 4-hour cost, same boundary as the model (fully financed installed system). The model reproduces it at 4 h by construction of the NREL equation, so it places other durations, it does not validate the 4-hour point.

Method: PNNL-33283 Eq. 1-3. LCOS = (CRF x CAPEX + fixed O&M) / energy delivered + charging price / RTE. CAPEX from the NREL 2025 split (energy cost x energy + power cost x power), converted at the ECB 2024 rate. Energy delivered = nameplate energy x DOD x cycles a year (PNNL Eq. 3).

Real terms: all costs in constant 2024 money with no escalation, annualised at a real discount rate. The yearly O&M exported to project mode is an undiscounted cash cost that does not depend on the discount rate.

Scope: standalone cost of storage. No arbitrage, capacity or ancillary-service revenue, no tax or subsidy; those belong to project mode.

Duty for which the NREL 4 % fixed O&M holds the plant at rated capacity. It is the validity limit of the only replacement model used here; the cycles and depth sliders (at most 365 x 90 % = 328.5 equivalent cycles a year) stay below it.

Turns the NREL one-cycle-a-day basis into cycles a year.

Market range Exact by definition.

Degradation: one replacement model, the NREL 2025 flat rate. The 4 % fixed O&M is set by NREL so that the plant performs at rated capacity throughout its life at about one cycle a day (p.11); delivered energy is therefore held at its rated value and no cell replacement or augmentation is costed separately. A cycle-life-driven replacement (such as the PNNL-33283 2,400-cycle LFP case with its own 0.43 % O&M and DC block prices) is a different model and is not mixed in. At much higher cycling NREL warns the rate may not suffice; the duty output shows where the user stands against that basis.

DC part of the 2-hour utility-scale Lazard case, the large-size anchor of the fixed project cost.

AC part of the 2-hour utility-scale Lazard case, divided by its 2-hour duration.

EPC part of the 2-hour utility-scale Lazard case.

DC part of the 2-hour, 2 MWh Lazard case: a single-container-size standalone system, the small-size anchor of the fixed project cost.

AC part of the 2-hour, 2 MWh Lazard case, divided by its 2-hour duration.

EPC part of the 2-hour, 2 MWh Lazard case.

Both size anchors share the same 2-hour duration, 1 cycle a day, 350 days and 90 % depth, so their cost gap is a size effect, not a duration effect.

Energy of the large Lazard size anchor.

Energy of the small Lazard size anchor, the size of one Huawei LUNA2000-2.0MWH container.

Size: CAPEX = proportional part + fixed project cost. The fixed cost is derived from Lazard 2025 at equal duration (2 h): the 1 MW/2 MWh standalone system costs 483.5 USD/kWh all-in (DC + AC/2 h + EPC midpoints) against 278 USD/kWh for 100 MW/200 MWh; spreading that gap over 2 and 200 MWh gives about 415,000 USD (383,500 EUR) of cost that does not scale with size (permitting, interconnection, engineering, management: the 'Fixed' items NREL lists in its cost categories). The NREL 2025 figure already carries that fixed cost spread over its 240 MWh reference, so the specific CAPEX is the NREL value plus the fixed cost x (1/E - 1/240 MWh). It rises steeply at single-container size (+190 EUR/kWh at 2 MWh) and is flat at utility scale (-1.2 EUR/kWh at 1,000 MWh). Calibrated on one pair of Lazard cases: medium evidence. Lazard's C&I case is behind the meter; a grid-connected single container may carry a larger interconnection cost.

Descriptor shown on the page, not used in any formula: the size law is the fixed project cost, whose local exponent goes from about 0.71 at single-container size to 1.0 at utility scale. The page measures the local exponent at the current size.

Low end of all-in 4-hour utility costs in 2025, the reference for the 200 EUR/kWh floor of the Customized slider (lowered from 250).